请教sigma delta AD的参考电平电路怎么做

tjjbraye · 发表于 2011-2-22 09:50:38

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sdm的Fs=1M，OSR=1024，参考电平要怎么考虑啊？有没有什么好的资料可以参考，谢谢

goodsilicon · 发表于 2011-2-22 11:28:20

Fs=1M，OSR=1024, 这么牛？？
做什么用啊？ OSR=1024 ?????????????????????

tjjbraye · 发表于 2011-2-22 16:11:59

sdm本身不是我做的，我就负责做两个参考电平
做什么用，这个不方便说啊

gaojun927 · 发表于 2011-2-26 21:46:35

最简单的用电源电压，一切ok

sdmout · 发表于 2011-2-27 20:18:04

This is a tricky question. If the SDM has a moderate dynamic range, the Vref can be generated on chip. Using a bandgap reference to drive a fully-differential amplifier will give Vhigh and Vlow, and therefore the Vref. The design of the fully-differential amplifier with minimum power requires a bit of knowledge. There is a document from Analog Device talking about this.

If your SDM has a very high SNDR, say >100dB, then Vref is good to be off-chip. Just my two cents.